fungsi f(x) = ax + b , jika f(3) = 5 fan f(1) = -3 , nilai f(4)

f(x) = ax + b
f(3) = 3a + b = 5
f(1) = a + b = -3
eliminasi b
2a = 5 - (-3) = 5 + 3 = 8
a = 8/2 = 4
subtitusi a
3a + b = 5
3.4 + b = 5
12 + b = 5
b = 5 -12 = -7

f(4) = a.4 + b = 4.4 + (-7)
16 + (-7) = 9